what happens if the earths core burns out

[the millster]

is there a brainiac out there that can answer this question that has been baffling me for ages and that is if the earths core should burn out would this planet still sustain life or would it be game over?

[scotstone]

The Earth's core is not burning, it is iron in a molten state. This molten state is maintained by convection movement and nuclear reactions and has been for billions of years and will continue for the foreseeable future.

[the millster]

Thanks for your answer, I am still slightly confused as I was watching a programme about planets and the search for life on them and on this programme it said that the planet was dead (the core at least) so I was wondering if this can/will happen to our planet.

[scotstone]

It is possible that the core of a planet could cool down if there is an insufficient heat source. It is thought that the core of Venus (which is thought to be metallic) has cooled down possibly because of its slow rotation and is solid. This solidity also means that Venus does not have a magnetic field. This cooling would have occurred billions of years ago. Mars and Mercury are both thought to have liquid cores.

[mibn2cweus]

It is believed that motion within the outer molten core of the Earth generates the magnetic field that envelopes the Earth and protects the surface of our planet from the Solar Wind and cosmic rays that would be harmful to life if they penetrated the Earth's atmosphere.

[jake-the-peg]

However the loss of the Earth's magnetic field might not be as catastrophic as all that. The Earth's magnetic field has 'flipped' a number of times in the past. In that the poles reversed.

Although 'flipped' makes it sound rapid this is likely to have slowly taken place over a period of 100 years or so - rapid only in geological terms.

More importantly the Earths core powers the long term carbon cycle and if this stopped volcanoes would stop releasing carbon dioxide into the atmosphere and the temperature would plummet.

Mars is a fair bit smaller than the Earth and it looks like it's core cooled down and this may be what happened to it. There was once liquid water on the surface of Mars and volcanoes.

If you want to see what the Earth would be like without volcanicity Mars is a good place to start.